Abstract: The relationship between geometrical factors of seismic intensity distribution and hypocentral parameters of strike-slip earthquake is considered by means of a simplified elliptic model of hypocentre in which the effects of environmental stiffness of hypocentral region and nonuniform resistance along fault zone are taken into account, and a new method, so-called isoseisms method, is developed preliminarily for estimating stress drop and slip displacement of historical earthquake. Also, the relationship between axes ratio of hypocentral ellipse and orientation of maximum principal stress relative to fault zone is presented in this paper. The method has been examined by estimating the hypocentral parameters of Tangshan(1976), Tonghai (1970), Luhuo(1973) and Yongshan (1974) earthquakes and comparing them with those estimated by the traditional methods.

Key words: Isoseisms, Hypocentral parameter, Stress drop, Slip displacement Sliding angle

摘要： 本文在考虑环境刚度效应和非匀阻效应的情况下,采用椭圆形震源简化模型,研究了走滑断层的地震烈度几何要素与震源参数之间的关系,初步建立了估计断层有效发震段长度、错动角、应力降和错动距离等参数的等震线法,并结合唐山、通海、炉霍和永善等震例进行了试算。

关键词: 等震线, 震源参数, 应力降, 断层错距, 断层错动角